As computer technology continues to advance, electronic and electrical components such as central processing units (CPUs) and power supply units (PSUs) of computers are providing faster operational speeds and greater functional capabilities. When a CPU or a PSU operates at a high speed or a high capacity in a computer enclosure, its temperature may increase greatly. It is desirable to quickly dissipate the heat generated by the CPU or the PSU.
Numerous kinds of heat pipes have been developed for cooling electronic components. Conventionally, a heat pipe comprises an evaporator section to take in heat and a condenser section to pass out heat. Working fluid is contained in the heat pipe to transfer heat from the evaporator section to the condenser section. Heat entering the evaporator section of the heat pipe boils the fluid and turns it into a vapor. The vapor expands in volume and travels to the condenser section where it condenses to a liquid and releases its heat. The liquid is then returned to the evaporator section by gravity and/or a wick, whereupon the cycle starts again.
A conventional heat pipe does not begin to work until the electronic/electrical component to be cooled has reached a threshold temperature high enough to evaporate the working fluid. In general, the threshold temperature is between 30° C. and 40° C. That is, the electronic/electrical component must operate at a temperature of at least 30° C. One solution to decrease the threshold temperature of the working fluid is to improve the vacuum inside the heat pipe. However, this commonly requires high rigidity materials for the heat pipe shell, which increases the cost of manufacturing the heat pipe. Further, even slight damage to the heat pipe may result in leakage of air into the heat pipe and an increase in the vacuum pressure of the heat pipe. If this happens, the heat pipe may fail to work altogether.
A heat pipe generally has a variety of other limitations, such as a capillary pumping rate limit, a nucleate boiling limit and an entrainment limit, all of which constrain the ability of the heat pipe to cool electronic/electrical components. When the first of any of these limitations is reached, the heat pipe cannot provide any further improvement in its operating capacity. What is needed, therefore, is an improved heat pipe which can efficiently conduct heat from a heat generating component. What is also needed is a method for making such heat pipe.